One of the top priorities of the Republican-led Congress and the Trump administration is repealing and replacing the Affordable Care Act (ACA), President Barack Obama’s landmark health care law.

Even supporters of the ACA want to repair its flaws, such as a lack of competition in some state insurance marketplaces. But because the ACA has also made major improvements to the health sector, it will be very difficult to craft a replacement that doesn’t disrupt insurance markets or increase the ranks of the uninsured.

During the campaign, President Donald Trump promised that the ACA’s successor will be “terrific,” an adjective that may have reassured some voters. After all, except for the individual mandate to purchase insurance, most parts of the ACA are popular with the public.

But the word “terrific” also hints at the best way Democrats can influence the revision of the ACA, as well as ensure that any problems that emerge can be fixed by Congress.

The ACA’s results

In many respects, the ACA has been a success.

Last December, the Obama administration’s Council of Economic Advisers released a long report that extensively documented the positive effects of the ACA. That’s an assessment backed up by independent experts, such as the Kaiser Family Foundation.

Few people know, however, that the Obama administration established official goals for the ACA and reported data on how well those goals were met.

This was required under the GPRA Modernization Act (GPRAMA), which was passed in 2010 to improve the 1993 Government Performance and Results Act (GPRA).

The 1993 law required departments to prepare strategic plans and report on performance. This helped the executive branch measure results and manage operations, but it did not encourage coordination over goals that crossed jurisdictional boundaries.

Congress crafted GPRAMA to reduce that problem by formalizing mechanisms for better coordination. And so now the executive branch must declare its priority goals across all major departments, and their leaders must hold quarterly reviews of the extent of progress toward those goals.

Some of the goals the Obama administration set for the health sector included how many people it aimed to enroll in the new health insurance marketplaces, the share of the non-elderly population still uninsured and hospital readmission rates.

As one example, the Health and Human Services Department wanted to get 10 million people enrolled in ACA health insurance marketplaces in 2016, up from its target of 9 million the year before. In March 2016, the department reported that it had surpassed its goal by 2.7 million. (This doesn’t count the additional millions who received insurance through the expansion of Medicaid.)

The Byrd rule roadblock

The House GOP’s 2016 “A Better Way” plan for health care promised generally to “provide all Americans with more choices, lower costs and greater flexibility.” It proposed many changes to the ACA, but—unlike the Obama administration’s targets—did not specify any expected outcomes from their plan.

Some Republican health policy experts who oppose the ACA recently warned that repealing the law but delaying a replacement would disrupt insurance markets. Democratic defenders of the law argue, with much logic, that it will be very hard to develop better alternatives to most of the ACA’s popular provisions, such as free preventive services and the prohibition against excluding people with pre-existing conditions from coverage.

In January, the GOP took a first step toward repealing the ACA, passing a fiscal year 2017 budget resolution that aims to “fast-track” the process by instructing committees to use a budget procedure known as “reconciliation.” In the modern Senate, because the minority can threaten a filibuster, it takes 60 votes to pass important bills. Reconciliation, in contrast, requires only a simple majority.

Democrats themselves used reconciliation in 2010 to pass part of the ACA after they lost their 60-vote majority.

But there is a limit to how Republicans can use reconciliation to get around Democratic objections. Reconciliation bills must comply with the Byrd rule, a three-decade-old Senate rule.

Like many Senate rules, the Byrd rule is complicated enough that the Senate parliamentarian will be called upon to interpret what it allows and what it does not. Primarily, it aims to ensure reconciliation bills are budgetary in nature by affecting spending or revenue. But one of its elements also says that provisions with a different purpose from the bill in question—such as, in the ACA repeal’s case, killing a health care regulation—have to be excluded. And since the health sector is very complex, any effort to repeal and replace the ACA would have many provisions that would be prohibited by the Byrd rule.

This means that at least part of any attempt to repeal and replace the ACA will have to go through regular legislative procedure, allowing Democrats to amend the proposed bill.

One caveat: It’s possible that Republicans will simply nix the Byrd rule, similar to how they’re considering “going nuclear” by getting rid of the Senate filibuster for Supreme Court nominations. But let’s assume for the moment that they don’t.

Making the ACA replacement ‘terrific’

This procedural roadblock is what creates the opportunity for Democrats to insist that a replacement of the ACA be, in fact, “terrific.”

In the Senate, Democrats could propose amendments to a replacement bill that would set specific goals of access, cost and quality—essentially requiring Trump to take responsibility for his promises that the replacement will be, in his words, “insurance for everybody.”

Following a “first do no harm” principle, these goals could be based on projected levels under current law.

After many years of vociferously criticizing the ACA, Republicans should be willing to be held accountable for the results of repealing and replacing it.

A third ‘R’: Repeal, replace and revise

The new law should also set up a process for reviewing attainment of those goals and for revising the law if it turns out to be flawed.

When Congress considers a replacement for the ACA, the nonpartisan Congressional Budget Office will project the new law’s likely effects. But given the complexity of the health sector, even projections from these expert analysts will inevitably be wrong.

So though repeal and replacement will be a stressful experience, Congress should not then expect years of rest and relaxation. In order to conduct oversight on the transition to a new health system, Congress should insist that the Trump administration declare goals, conduct quarterly reviews of results and report on its performance to Congress and the public.

To reassure the many people worried about the GOP’s “cure” being worse than the disease, Congress could also promise—in the repeal-and-replace legislation—to hold votes on revising the law during the next session of Congress, which begins in 2019. That is, if a provision is found to come up short of its goals or desperately needs revision, there would be a fast-track process to fix any problem or revert to the ACA original.

While including this process would not amount to an ironclad promise—because the majority can effectively determine the rules for each Congress—it would be a commitment that would be broken only in bad faith.

Some revision of the ACA is inevitable and even desirable.

If Democrats and Republicans jointly agree on establishing specific goals for the reform, building on the existing process for monitoring attainment of those targets, it could lead to measurable improvements in the health system. In doing so, the “repeal and replace” campaign slogan could be transformed into “repair with results.”

The alternative could be attractive to politicians who wish to avoid responsibility for their actions. However, many negative outcomes from the new system will be more than obvious to the patients who lack quality health insurance.

If that happens, they won’t be tweeting the word “terrific.” Instead they will more likely to be “SAD!” and “MAD!”

Roy T. Meyers is Professor of Political Science and Affiliate Professor of Public Policy, University of Maryland, Baltimore County.